Antibody Titration

Principle:

The purpose of antibody titration is to determine how to follow a pregnancy at risk for hemolytic disease of the fetus and newborn (HDFN) or for organ transplant (e.g. ABO-incompatible renal or stem cell transplantation).

Titers are notoriously hard to compare across different institutions and different reagents and are subject to variation between technologists. Automated methodologies may help limit this variability.

Policy:

  1. Indications
    1. Pregnant patients with active anti-D to determine if a more aggressive intervention, e.g. percutaneous umbilical blood sampling, is needed to further assess the state of the fetus
    2. ABO-incompatible renal transplantation:  to determine candidacy and follow the effect of ABO column immunoadsorption and immunosuppression
    3. ABO-incompatible stem cell transplantation to follow the course of treatment
    4. External proficiency surveys
  2. Procedure and Interpretation:
    1. Titers may be done in saline or at antiglobulin phase.
    2. Titers may be performed manually or on automated equipment (e.g. Ortho Vision Max).
    3. If the titers are to be used as part of an external protocol, the method should be correlated with the external institution and found to be acceptable.
    4. Titers for organ transplant (e.g. kidney) will be done at saline and antiglobulin phase.
    5. The titer FOR PATIENT REPORTING is defined as the final tube showing a 1+ reaction.
    6. The titer for CAP surveys will be according to the instructions of the CAP, even it does not agree with our 1+ reaction rule.
    7. Any variances from this policy must be specifically approved by a blood bank consultant.

References:

  1. Technical Manual, Current Edition, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services Current Edition, AABB, Bethesda, MD, USA